Methods for etching an etching stop layer disposed on the substrate using a cyclical etching process are provided. In one embodiment, a method for etching an etching stop layer includes performing a treatment process on the substrate having a silicon nitride layer disposed thereon by supplying a treatment gas mixture into the processing chamber to treat the silicon nitride layer, and performing a chemical etching process on the substrate by supplying a chemical etching gas mixture into the processing chamber, wherein the chemical etching gas mixture includes at least an ammonium gas and a nitrogen trifluoride, wherein the chemical etching process etches the treated silicon nitride layer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for etching an etching stop layer comprising: (a) performing a treatment process on the substrate having a silicon nitride layer disposed thereon by supplying a treatment gas mixture into the processing chamber to treat the silicon nitride layer; (b) performing a chemical etching process on the substrate by supplying a chemical etching gas mixture into the processing chamber, wherein the chemical etching gas mixture includes at least an ammonium gas and a nitrogen trifluoride, wherein the chemical etching process etches the treated silicon nitride layer; and repeatingly performing step (a)-step (b) to etch the silicon nitride layer until an underlying substrate is exposed.
2. The method of claim 1 , further comprising: (c) performing a transition process on the etched substrate by supplying a transition gas mixture into the processing chamber after performing step (b).
3. The method of claim 2 , wherein the transition gas mixture includes at least a hydrogen containing gas, a nitrogen containing gas or an inert gas.
4. The method of claim 2 , further comprising: repeatingly performing step (a)-step (c) to etch the silicon nitride layer until an underlying substrate is exposed.
5. The method of claim 2 , wherein performing the transition process further comprises: supplying the transition gas mixture to remove etching residual without applying a RF power.
6. The method of claim 1 , wherein the treatment gas mixture includes at least a hydrogen containing gas, a nitrogen containing gas or an inert gas.
7. The method of claim 1 , wherein performing the treatment process on the substrate further comprises: applying a RF bias power to the treatment gas mixture.
8. The method of claim 1 , wherein performing the chemical etching process on the substrate further comprises: applying a RF source power to the chemical etching gas mixture remotely from the processing chamber.
9. The method of claim 1 , wherein performing the chemical etching process on the substrate further comprises: supplying the ammonium gas and the nitrogen trifluoride in the chemical etching gas mixture a molar ratio of from about 5:1.
10. The method of claim 1 , further comprising: maintaining a substrate temperature between about 50 degrees and about 150 degrees Celsius.
11. The method of claim 1 , wherein the silicon nitride layer is an etching stop layer utilized in a contact structure in a semiconductor device.
12. A method for etching an etching stop layer comprising: (a) transferring a substrate having a silicon nitride layer disposed thereon in a processing chamber, wherein a patterned silicon oxide layer along with a pattered mask layer disposed on the silicon nitride layer exposing a portion of the silicon nitride layer; (b) supplying a treatment gas mixture to treat the exposed portion of the silicon nitride layer, wherein the treatment gas mixture includes an inert gas; and (c) supplying a chemical etching gas mixture into the processing chamber, wherein the chemical etching gas mixture includes at least an ammonium gas and a nitrogen trifluoride to etch the treated silicon nitride layer; and repeatingly performing steps (b) and (c) until the exposed portion of the silicon nitride layer is removed from the substrate.
13. The method of claim 12 , further comprising: (d) supplying a transition gas mixture to the processing chamber, wherein the transition gas mixture includes an inert gas after performing step (c).
14. The method of claim 12 , wherein the ammonium gas and the nitrogen trifluoride in the chemical etching gas mixture a molar ratio of from about 3:1 to about 30:1.
15. The method of claim 12 , further comprises: applying a RF bias power to the treatment gas mixture; applying a RF source power remotely from the processing chamber to the chemical etching gas mixture.
16. The method of claim 13 , wherein supplying the transition gas mixture further comprises: supplying the transition gas mixture to remove etching residual without applying a RF power.
17. A method for etching a silicon nitride layer comprising: (a) transferring a substrate having a silicon nitride layer disposed on a metal silicide structure into a processing chamber, wherein the silicon nitride layer has a patterned silicon oxide layer along with a pattered mask layer disposed thereon exposing a portion of the silicon nitride layer; (b) supplying a Ar or He gas while applying a RF bias power to treat the exposed silicon nitride layer; (c) supplying a chemical etching gas mixture including at least an ammonium gas and a nitrogen trifluoride while applying a RF source power remotely from the processing chamber to etch the treated silicon nitride layer; and (d) supplying a Ar or He gas to the processing chamber without applying a RF power.
18. The method of claim 17 , further comprising: repeatedly performing steps (b) to (d) until the exposed portion of the silicon nitride layer is removed exposing the underlying metal silicide structure.
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September 17, 2013
March 17, 2015
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